The present invention generally relates to a management computer, a power supply control method and a computer system, and, for instance, can be suitably applied to a computer system that performs power supply control of a plurality of storage apparatuses.
In recent years, data handled by corporations and individuals is becoming diversified and, together with the mandatory long-term storage of electronic data, the data volume to be stored in storage apparatuses is increasing rapidly. Thus, in order to realize flexible scalability and reduction in management costs based on uniform management, a computer system is adopting a storage network configuration (primarily known as SAN (Storage Area Network) which connects a plurality of servers and a plurality of storage apparatuses with the likes of a switch or a hub. A computer system is constantly demanded of higher sophistication and lower prices. Recently, environmental issues are becoming an increased center of focus, and energy conservation is also being demanded.
In order to conserve energy in a computer system, with respect to a stand-alone memory apparatus (hereinafter also referred to as a storage apparatus), disclosed is technology of monitoring the volume access frequency from a host computer using a storage extent (hereinafter also referred to as a volume) of the storage apparatus, and changing a disk device configuring the volume to an energy conservation mode when the volume is not accessed for a prescribed period of time, or turning off the power supply (energy conservation processing), and technology of executing diagnosis to maintain the reliability of the disk device subject to the energy conservation processing after the lapse of a prescribed period of time from the start of energy conservation processing, or when it becomes a designated time (for instance, refer to Japanese Patent Laid-Open Publication No. 2000-293314).
Further, with respect to a storage system having a plurality of storage processors for processing data access requests from a host computer in a storage apparatus, disclosed is technology of balancing/integrating the access load in different storage processors according to the access load fluctuation (IOPS (Input/Output per second) fluctuation) of the storage processor so as to improve the response to the data access from the user, and migrating storage processors not subject to a load to a sleep mode so as to improve the power efficiency (for instance, refer to Japanese Patent Laid-Open Publication No. 2003-296153).
The power supply control technology of disk devices in a storage apparatus disclosed in Japanese Patent Laid-Open Publication No. 2000-293314 describes the performance of power supply control of disk devices in the storage apparatus according to the volume access frequency of the host computer using the volume. Further, the power supply control of a storage processor in the storage system disclosed in Japanese Patent Laid-Open Publication No. 2003-296153 describes the performance of power supply control of the storage processor in the storage system according to the access frequency of data in the computer using such data stored in the storage system.
Nevertheless, with the foregoing power supply control technologies according to the data access frequency, since power supply control is also performed to the accidental increase or decrease in the access frequency, it is necessary to repeat the turn-on and turn-off of the power supply in short intervals, and there is a problem in that the power consumption will increase in apparatuses in which the incoming current when the power supply is turned on is greater than the ordinary current.
Further, components and the main power supply (power supply of the case) other than the disk devices and storage processors are constantly in operation, and consume extra power. Therefore, with a computer system including a plurality of storage apparatuses, extra power to operate components and the main power supply other than the disk devices is required, and there is a problem in that extra power consumption will increase in proportion to the number of storage apparatuses.